Re: [PATCH v2.1 1/2][BZ #16274] Fix shm_open.

[OndÅej BÃlka <neleai at seznam dot cz>]

On Fri, Nov 29, 2013 at 02:48:31PM -0500, Carlos O'Donell wrote:
> > +      if (errno != ENOSYS)
> 
> Same question here, shouldn't this be "errno == ENOSYS"?
> 
> > +        error (EXIT_FAILURE, 0, "failed to open shared memory object: shm_open");
> > +
> 
> Suggest: "Failed to open shared memory object: shm_open unimplemented. Test skipped." wrapped appropriately.
> 
> >        perror ("failed to create a shared memory object: shm_open");
> >        return 0;
> 
> Shouldn't this be `return -1;' ?
> 
> We want to exit with 0 if the error was ENOSYS otherwise -1?
> 
> Maybe it's just Friday and I'm confused though...
> 
It was double negation, which is correct but bit confusing.

Here is new version, a do_open function uses a existing shared object so
I simply inlined it with appropriate error. 


	[BZ #16274]
	* sysdeps/unix/sysv/linux/shm_open.c (shm_open): Correctly
	handle filename validation.                               
	* rt/tst-shm.c (do_test): Do not skip a test when
	shm_open fails.
	(do_open): Delete.


diff --git a/rt/tst-shm.c b/rt/tst-shm.c
index cb4b1ee..83ad586 100644
--- a/rt/tst-shm.c
+++ b/rt/tst-shm.c
@@ -34,34 +34,17 @@
 /* We want to see output immediately.  */
 #define STDOUT_UNBUFFERED
 
-
-static int
-do_open (void)
-{
-  int fd;
-
-  /* Create the shared memory object.  */
-  fd = shm_open ("/shm-test", O_RDWR, 0600);
-  if (fd == -1)
-    {
-      /* We don't regard this as a bug.  Simply don't run the test.  It could
-	 means there is no such implementation or the object is already in
-	 use in which case we don't want to disturb.  */
-      perror ("failed to open shared memory object: shm_open");
-      return -1;
-    }
-
-  return fd;
-}
-
-
 static void
 worker (int write_now)
 {
   struct timespec ts;
   struct stat64 st;
   int i;
-  int fd = do_open ();
+  int fd = shm_open ("/glibc-shm-test", O_RDWR, 0600);
+
+  if (fd == -1)
+    error (EXIT_FAILURE, 0, "failed to open shared memory object: shm_open");
+
   char *mem;
 
   if (fd == -1)
@@ -143,14 +126,17 @@ do_test (void)
 
 
   /* Create the shared memory object.  */
-  fd = shm_open ("/shm-test", O_RDWR | O_CREAT | O_TRUNC | O_EXCL, 0600);
+  fd = shm_open ("/glibc-shm-test", O_RDWR | O_CREAT | O_TRUNC | O_EXCL, 0600);
   if (fd == -1)
     {
-      /* We don't regard this as a bug.  Simply don't run the test.  It could
-	 means there is no such implementation or the object is already in
-	 use in which case we don't want to disturb.  */
-      perror ("failed to create a shared memory object: shm_open");
-      return 0;
+      /* If shm_open is unimplemented we skip the test.  */
+      if (errno == ENOSYS)
+        {
+	  perror ("shm_open unimplemented.  Test skipped.");
+          return 0;
+        }
+      else
+        error (EXIT_FAILURE, 0, "failed to create shared memory object: shm_open");
     }
 
   /* Size the object.  We make it 4000 bytes long.  */
@@ -160,18 +146,18 @@ do_test (void)
          shared memory itself.  */
       perror ("failed to size of shared memory object: ftruncate");
       close (fd);
-      shm_unlink ("/shm-test");
+      shm_unlink ("/glibc-shm-test");
       return 0;
     }
 
   if (fstat64 (fd, &st) == -1)
     {
-      shm_unlink ("/shm-test");
+      shm_unlink ("/glibc-shm-test");
       error (EXIT_FAILURE, 0, "initial stat failed");
     }
   if (st.st_size != 4000)
     {
-      shm_unlink ("/shm-test");
+      shm_unlink ("/glibc-shm-test");
       error (EXIT_FAILURE, 0, "initial size not correct");
     }
 
@@ -184,7 +170,7 @@ do_test (void)
       /* Couldn't create a second process.  */
       perror ("fork");
       close (fd);
-      shm_unlink ("/shm-test");
+      shm_unlink ("/glibc-shm-test");
       return 0;
     }
 
@@ -199,7 +185,7 @@ do_test (void)
       kill (pid1, SIGTERM);
       waitpid (pid1, &ignore, 0);
       close (fd);
-      shm_unlink ("/shm-test");
+      shm_unlink ("/glibc-shm-test");
       return 0;
     }
 
@@ -208,14 +194,14 @@ do_test (void)
   waitpid (pid2, &status2, 0);
 
   /* Now we can unlink the shared object.  */
-  shm_unlink ("/shm-test");
+  shm_unlink ("/glibc-shm-test");
 
   return (!WIFEXITED (status1) || WEXITSTATUS (status1) != 0
 	  || !WIFEXITED (status2) || WEXITSTATUS (status2) != 0);
 }
 #define TEST_FUNCTION do_test ()
 
-#define CLEANUP_HANDLER shm_unlink ("/shm-test");
+#define CLEANUP_HANDLER shm_unlink ("/glibc-shm-test");
 
 
 #include "../test-skeleton.c"
diff --git a/sysdeps/unix/sysv/linux/shm_open.c b/sysdeps/unix/sysv/linux/shm_open.c
index 482b49c..7bb2874 100644
--- a/sysdeps/unix/sysv/linux/shm_open.c
+++ b/sysdeps/unix/sysv/linux/shm_open.c
@@ -151,7 +151,7 @@ shm_open (const char *name, int oflag, mode_t mode)
   namelen = strlen (name);
 
   /* Validate the filename.  */
-  if (name[0] == '\0' || namelen > NAME_MAX || strchr (name, '/') == NULL)
+  if (name[0] == '\0' || namelen > NAME_MAX || strchr (name, '/') != NULL)
     {
       __set_errno (EINVAL);
       return -1;
@@ -241,7 +241,7 @@ shm_unlink (const char *name)
   namelen = strlen (name);
 
   /* Validate the filename.  */
-  if (name[0] == '\0' || namelen > NAME_MAX || strchr (name, '/') == NULL)
+  if (name[0] == '\0' || namelen > NAME_MAX || strchr (name, '/') != NULL)
     {
       __set_errno (ENOENT);
       return -1;